On the touchline, Gernot Rohr remained stony-faced, looking for all the world like a disappointing statue of Rupert Murdoch. He must, though, have been delighted with what he saw on the pitch, his Gabon team – in the first half in particular – playing with real pace and intelligence, executing what was presumably a deliberate tactical plan to perfection as they won their opening game at the Africa Cup of Nations 2-0.

Yes, it was only against Niger, who lost all three of their away games in qualifying and sneaked through thanks to the failings of Egypt – an ageing squad distracted by the uprising against Hosni Mubarak – and South Africa – overwhelmed by administrative idiocy that meant they misunderstood the qualification criteria and played for a draw in their final game when they needed a win. That is not to diminish Niger's achievement; for a nation listed second bottom of the UN's human development index to qualify is a bona fide fairy story. So impoverished is the federation that one of its coaching staff, Frederic Acosta, who played in the side that nearly qualified for the Cup of Nations in 1982, trawls the kiosks of Niamey collecting the conical display units used for lollipops rather than buying training cones.

After five successive years of drought, the rains failed again last year, resulting in a 25% reduction in the harvest across the Sahel. Oxfam and players from Niger, Mali, Burkina Faso and Senegal have been working at the tournament to try to promote awareness of a mounting crisis.

But still, it was only Niger; for Gabon there will be much tougher tests ahead. But what must have pleased Rohr beneath the impassive facade was that this was the sort of game that might have tripped his side up. They are noted for their caution. They like to play a 5-4-1 and catch sides on the break. In friendlies against Ghana and Brazil before Christmas, they were dourly resolute, conceding two in each. Against Sudan and Burkina Faso in the buildup to the tournament, they could only draw 0-0. The question on Monday was whether Gabon could find an attacking edge.

Certainly in the first half they could, and impressively so. The back five had gone, replaced by a back four with two attacking full-backs. The right-back, Edmond Mouele, was impressive, tearing forward and overlapping at every opportunity. Levy Madinda, a 19-year-old on the books of Celta Vigo, sat deep in midfield, offering cover. He was flanked by the Bordeaux 18-year-old André Biyogo Poko and the experienced Cédric Moubamba in a three-man midfield.

What was really interesting, though, was the front three. Stéphane Nguema operated on the right, drifting infield just enough to create space for Mouele's overlaps, leaving poor Mohamed Soumaïla, the Niger left-back, horribly exposed. Pierre-Emerick Aubameyang, who came through the Milan youth set-up and is now at St Etienne, is the natural leader of the line, but he frequently drifted from centre-forward to a centre-left position, swapping over with Eric Mouloungui of Nice. The result was a simple pattern: work the ball to the right, double up on Soumaïla, cross it, and have Aubameyang coming in at the back post.

The warning signs were there early: with 18 minutes gone, a Mouele cross from the right looped off a defender and over Aubameyang for Mouloungui, who snatched at the chance and drilled it into the body of Kassaly Daouda. Niger, though, were unable to staunch the flow; Mouele played a neat first-time pass to Nguema, his cross eluded Kassaly, and Aubameyang headed the opener just after the half-hour. The second, on the stroke of half-time, came down the left, Nguema following in after Kassaly had parried an Aubameyang header.

Gabon are one of the success stories of African football. Having qualified for the Cup of Nations for the first time in 1994, they reached the quarter-finals in South Africa in 1996 (although that was largely down to Nigeria's withdrawal following South African condemnation of the execution of Ken Saro-Wiwa. They qualified again in 2000, but missed out on the next four tournaments until Alain Giresse took charge.

Gabon began the qualifying series for the last World Cup with two victories; Cameroon, in the dog days of the Otto Pfister reign, struggled, taking only a point from their first two games. They were scheduled to meet in Libreville in June 2009. But then Omar Bongo, who had been president for 41 years, died and the game was postponed as part of a national week of mourning. By the time it was rearranged, for September, Cameroon had regrouped under Paul Le Guen. Cameroon beat them home and away in the space of four days and qualified ahead of them. The Panthers had their revenge in the Cup of Nations, winning 1-0 in Lubango thanks to a top-class display from the goalkeeper Didier Ovono, but went out on goals scored in a three-way head-to-head with Zambia and Cameroon (embarrassingly, like South Africa in qualifying this time round, they initially celebrated despite defeat to Zambia in their final game, believing they had gone through).

Essentially Rohr has built on the foundations Giresse left, and has benefited from the emergence of gifted young players who carried Gabon to qualification for the Olympics. There were concerns that success may have raised unrealistic expectations, but the evidence of the opening game – albeit only against Niger – suggests a quarter-final is far from beyond Gabon.

The only doubt is whether they should have shut up shop at 2-0. Tunisia beat Morocco 2-1 in Group C's other fixture on Monday, but both sides played well enough to suggest this will be a tight three-way battle for the two qualifying slots. The worry is that Gabon could find goal-difference against them again.